Cutting apparatus and method of operating

ABSTRACT

A cutting apparatus suitable for creating tunnels and subterranean roadways includes independently pivoting supports that each carries a respective independently pivoting arm and a rotatable cutting head. Each cutting head via the supports and arms is configured to slew laterally outward in a sideways direction and to pivot in a vertical upward and downward direction. The supports and arms are mounted on a linear moving sled carried by a main frame.

RELATED APPLICATION DATA

This application is a § 371 National Stage Application of PCTInternational Application No. PCT/EP2015/072845 filed Oct. 2, 2015claiming priority of EP Application No. PCTEP2014071334, filed Oct. 6,2014.

FIELD OF INVENTION

The present invention relates to rock cutting apparatus suitable forcreating tunnels or subterranean roadways and in particular, althoughnot exclusively, to undercutting apparatus in which a plurality ofrotating heads are capable of being slewed laterally outward and raisedin the upward and downward direction during forward cutting. Theinvention also relates to a method of operating such cutting apparatus.

BACKGROUND ART

A variety of different types of excavation machines have been developedfor cutting drifts, tunnels, subterranean roadways and the like in whicha rotatable head is mounted on an arm that is in turn movably mounted ata main frame so as to create a desired tunnel cross sectional profile.WO2012/156841, WO 2012/156842, WO 2010/050872, WO 2012/156884,WO2011/093777, DE 20 2111 050 143 U1. All described apparatus for millcutting of rock and minerals in which a rotating cutting head forcedinto contact with the rock face as supported by a movable arm. Inparticular, WO 2012/156884 describes the cutting end of the machine inwhich the rotatable heads are capable of being raised and loweredvertically and deflecting in the lateral sideways direction by a smallangle in an attempt to try enhance the cutting action.

WO 2014/090589 describes a machine for digging roadways tunnels and thelike in which a plurality of cutting heads are movable to dig into therock face via a pivoting arcuate cutting path. US 2003/0230925 describesa rock excavator having a cutter head mounting a plurality of annulardisc cutters suitable to operate in an undercutting mode.

It has been observed that a transition from a stationary arrangement ofthe cutting apparatus to a configuration of the cutting apparatus whichallows for a movement of the overall cutting apparatus conventionallymay involve time-consuming configuration changes, which add up to anamount time in which the cutting apparatus is not in use per se, i.e. israther in preparation for the actual cutting.

Furthermore, it has been observed that conventional cutting machines arenot optimised to cut hard rock having a strength typically beyond 120MPa whilst creating a tunnel or subterranean cavity safely and reliablyof desired cross sectional configuration. Accordingly, what is requiredis a cutting machine that addresses these problems.

SUMMARY OF THE INVENTION

It is an objective to provide a cutting apparatus or machine and amethod of operation such cutting apparatus or machine allowing for animproved ratio of productive cutting operation to preparation procedure,during which no cutting is provided.

It is a further objective of the present invention to provide a cuttingmachine suitable to form tunnels and subterranean roadways beingspecifically configured to cut hard rock beyond 120 MPa in a controlledand reliable manner. It is a further specific objective to provide acutting machine capable of creating a tunnel with a variable crosssectional area within a maximum and a minimum cutting range. It is afurther specific objective to provide a cutting (excavator) machineoperable in an ‘undercutting’ mode according to a two stage cuttingaction.

The objective of allowing for the improved ratio is achieved byproviding a cutting apparatus suitable for creating tunnels orsubterranean roadways and the like comprising a main frame havinggenerally upward, downward and side facing regions, at least one armpivotally mounted via an arm pivot axis aligned in a direction extendingtransverse including perpendicular to a generally upright directionrelative to the upward and downward facing regions to enable the arm topivot relative to the main frame in an upward and downward directionrelative to the upward and downward facing regions, at least one armactuator to actuate pivoting movement of the arm relative to the mainframe, a rotatable cutting head mounted at the arm rotatable about ahead axis orientated to extend substantially transverse to the arm pivotaxis, a pair of crawler tracks or a set of wheels allowing a forward andrearward movement of the cutting apparatus over ground, and a set offloor engaging members mounted at the main frame, wherein the floorengaging members are extendable to provide a cutting mode of the cuttingapparatus, in which the cutting apparatus rests on the floor engagingmembers, and are retractable to provide a non-cutting mode of thecutting apparatus, in which the cutting apparatus rests on the pair ofcrawler tracks or set of wheels, wherein the pair of crawler tracks orthe set of wheels define a plane inclined relative to the main framesuch that upon changing from the cutting mode to the non-cutting modethe cutting head is raised away from the ground.

In this context, the invention further provides for a method ofoperating a cutting apparatus for creating tunnels or subterraneanroadways and the like, wherein the cutting apparatus comprises a mainframe having generally upward, downward and side facing regions, atleast one arm pivotally mounted via an arm pivot axis aligned in adirection extending transverse including perpendicular to a generallyupright direction relative to the upward and downward facing regions toenable the arm to pivot relative to the main frame in an upward anddownward direction relative to the upward and downward facing regions,at least one arm actuator to actuate pivoting movement of the armrelative to the main frame, a rotatable cutting head mounted at the arm,a pair of crawler tracks or a set of wheels allowing a forward andrearward movement of the cutting apparatus over ground, and a set offloor engaging members mounted at the main frame, wherein the methodcomprises a cutting step, a non-cutting step including a forward orrearward movement of the cutting apparatus over ground, a firsttransition step from the non-cutting step to the cutting step includingan extending of the floor engaging members such that cutting apparatusrests on the floor engaging members, and a second transition step fromthe cutting step to the non-cutting step including a retracting of thefloor engaging members such that the cutting apparatus rests on the pairof crawler tracks or set of wheels, wherein the pair of crawler tracksor the set of wheels define a plane inclined relative to the main framesuch that the second transition step includes a backward-tilting of thecutting apparatus, causing the rotatable cutting head to be raised awayfrom the ground.

The aspects of the invention discussed above address a forward and/orrearward movement of the main frame and the cutting apparatus in totalin relation to the ground, i.e. a relocation of the cutting apparatusrather than a reconfiguration in which only elements of the cuttingapparatus are arranged in a different relational manner.

That the cutting apparatus is in the non-cutting mode does notnecessarily imply that a cutting operation is not possible; as the focusof the non-cutting mode is that the apparatus is in a mode which enablesmovement of the cutting apparatus as a whole. It is preferred that thecutting is performed in the cutting mode, as in such case there isstabilization provided, while reaction forces from the cutting processare prevented from having effect on the crawler tracks or set of wheels(or the carriage to which these are mounted).

The functionality of securing or stabilizing the cutting machine isfulfilled by the engaging members, which are thus provided for movingthe cutting machine upwards and downwards. On the other side, thefunctionality of allowing for a forward and rearward movement of themachine is provided by the crawler tracks or set of wheels. In thismanner, simple and cost-effective structures may be used. In particular,preferably the pair of crawler tracks or set of wheels are basicallyfixed in term of an upwards or downwards movement (safe for ratherminute movements in the context of suspension and the like) and alsodefine the inclined plane in a fixed manner.

The lower surface(s) of the pair of crawler tracks or set of wheelsdefine a plane (which coincides with the ground when the cuttingapparatus is resting on the pair of crawler tracks or set of wheels),wherein this plane is inclined with respect to the main frame (oroverall cutting apparatus). When this is considered independently fromthe issue of whether or not the cutting apparatus is resting on theground (either on the floor engaging members or on the pair of crawlertracks or set of wheels), the above mentioned plane is oriented suchthat in a default position of the cutting head(s) with the arm beingsubstantially directed downwards or approximately downwards, there is apredetermined distance between the plane and the cutting head. Thisdistance corresponds, under the assumption of an even ground, to theclearance of the cutting head from the ground when the cutting machineis resting on the pair of crawlers or set of wheels.

Preferably, the inclination of the plane defined by the pair of crawlertracks or the set of wheels relative to the main frame is in the rangefrom 1° to 10°, preferably in the range of 2° to 6°, most preferablyapproximately 2°. It was found that by means of such an inclination aproper clearance can be achieved while avoiding an excessive tilting ofthe cutting apparatus. Phrased differently, preferably, the inclinationof the plane defined by the pair of crawler tracks or the set of wheelsrelative to the main frame is set such that the cutting head is raisedin an amount in the range from 3 cm to 30 cm, preferably in the range of6 cm to 20 cm, most preferably approximately 6 cm.

Further, preferably, the method of operating includes an adjustment stepof adjusting a direction and/or position of the cutting apparatus bymeans of the floor engaging members and/or the pair of crawler tracks orset of wheels. In particular, the attitude of the cutting apparatus inrelation to the ground corresponding to a certain extend to thedirection in which the cutting apparatus is facing (and cutting) can beadjusted by controlling an extent of extension or retraction of thefloor engaging elements separately.

The objective of allowing for the improved ratio is also achieved byproviding a cutting apparatus suitable for creating tunnels orsubterranean roadways and the like comprising a main frame havinggenerally upward, downward and side facing regions, a powered sledmovably mounted at the main frame and configured to slide in a forwardcutting direction of the cutting apparatus relative to the main frame,at least one arm pivotally mounted to the sled via an arm pivot axisaligned in a direction extending transverse including perpendicular to agenerally upright direction relative to the upward and downward facingregions to enable the arm to pivot relative to the main frame in anupward and downward direction relative to the upward and downward facingregions, at least one arm actuator to actuate pivoting movement of thearm relative to the main frame, and a rotatable cutting head mounted atthe arm, wherein the cutting apparatus further comprises engagingmembers mounted at the main frame, the engaging members including floorengaging members and at least one of roof engaging members and side wallengaging members, at least the floor engaging members being extendableand retractable to respectively raise and lower the apparatus in theupward and downward direction, wherein at least one roof or side wallengaging member is mounted to the powered sled and is configured forbeing extended for wedging the cutting apparatus in cooperation with theother engaging members in a cutting mode of the cutting apparatusbetween roof or side wall and floor.

In this context, the invention further provides for a method ofoperating a cutting apparatus for creating tunnels or subterraneanroadways and the like, wherein the cutting apparatus comprises a mainframe having generally upward, downward and side facing regions, apowered sled movably mounted at the main frame and configured to slidein a forward cutting direction of the cutting apparatus relative to themain frame, at least one arm pivotally mounted to the sled via an armpivot axis aligned in a direction extending transverse includingperpendicular to a generally upright direction relative to the upwardand downward facing regions to enable the arm to pivot relative to themain frame in an upward and downward direction relative to the upwardand downward facing regions, at least one arm actuator to actuatepivoting movement of the arm relative to the main frame, a rotatablecutting head mounted at the arm, and engaging members mounted at themain frame, the engaging members including floor engaging members and atleast one of roof engaging members and side wall engaging members, atleast the floor engaging members being extendable and retractable torespectively raise and lower the apparatus in the upward and downwarddirection, wherein at least one roof or side wall engaging member ismounted to the powered sled, wherein the method comprises an anchoringstep of extending at least the floor engaging member so to wedge thecutting apparatus between roof or side wall and floor, and an operationstep including an extending of the at least one roof or side wallengaging member mounted to the powered sled for cooperating with theother engaging members in wedging the cutting apparatus between roof orside wall and floor.

The following insight is underlying this aspect of the invention. As thecutting is performed by pivoting the arm in an preferably upwardsdirection, such cutting process does not include a movement of the sled,the sled is basically stationary during such process and may thereforebe involved in fixing or stabilizing the cutting machine against forcesfrom the cutting. This allows that the roof or side wall engagingelement is mounted to the sled, which in turn allows for an increasedstroke of the sled movement without increasing the overall size orlength of the cutting apparatus. With the possible extent of themovement of the sled being enlarged, the number of times of completecutting apparatus needs to be moved in total in order achieve a certaindistance in cutting is reduced.

In order to combine the above discussed aspects, the present inventionprovides further for an cutting apparatus according to the first aspectwhich further comprises a powered sled movably mounted at the main frameand configured to slide in a forward cutting direction of the cuttingapparatus relative to the main frame, wherein the at least one arm ismounted to the sled, and a set of roof or side wall engaging membersmounted at the main frame, wherein at least one roof or side wallengaging member is mounted to the powered sled and is configured forbeing extended for wedging the cutting apparatus in cooperation with theother engaging members in a cutting mode of the cutting apparatusbetween roof or side wall and floor.

Preferably, the floor engaging members are configured for arranging thecutting apparatus, in the cutting mode, such that the upward facingregion is horizontal and/or parallel to the ground. In particular, thefloor engaging members are configured for arranging the cuttingapparatus, in the cutting mode, such that a movement direction of thepowered sled is parallel to the ground. The floor engaging memberconfigured in such manner allow advantageously for an adjustment of theattitude of the cutting apparatus in relation to the ground.

Preferably, the engaging members include two front floor engagingmembers, two rear engaging members, two roof engaging members and theroof engaging member mounted to the sled, wherein the two roof engagingmembers are mounted to the main frame at a position backwards inrelation to the sled. The position of the two roof engaging membersbackwards in relation to the sled is not particularly limited and theseroof engaging members may be provided approximately in the middle of thecutting apparatus (in forwards/backwards direction) as well as in thebackwards portion of the cutting apparatus.

Preferably, the engaging members are each extendable and retractablelinearly by means of a respective control cylinder, in particular bymeans of a hydraulic cylinder.

Preferably, in regard to the above discussed method aspect of theinvention, the operation step further includes, after the extending ofthe engaging member, a cutting step including a pivoting of the armrelative to the main frame and a cutting by means of the cutting head,wherein the operation step further includes, after the cutting, aretracting of the engaging member and a moving of the sled. Theoperation step thus preferably includes an extending of the roof or sidewall engaging member (to secure the cutting apparatus), a cutting stepin which the arm (on which the cutting head is mounted) is pivoted andthe cutting head cuts the rock in front of the cutting apparatus(particularly in an undercutting manner), a retracting of the roof orside wall engaging member mounted to the sled and a moving of the sled(made possible due to the retracting of the engaging member which wouldotherwise block such movement). Preferably, the operation step includesmultiple repetitions of the extending, the cutting step and theretracting and moving in this order.

In combination of the above aspects, the invention also provides for amethod of operating according to the second aspect wherein the cuttingapparatus further comprises a pair of crawler tracks or a set of wheelsallowing a forward and rearward movement of the cutting apparatus overground, wherein the method further comprises a non-cutting stepincluding a forward or rearward movement of the cutting apparatus overground, a second transition step from the anchoring or operation step tothe non-cutting step including a retracting of the floor engagingmembers such that the cutting apparatus rests on the pair of crawlertracks or set of wheels, wherein the pair of crawler tracks or the setof wheels define a plane inclined relative to the main frame such thatthe second transition step includes a backward-tilting of the cuttingapparatus, causing the rotatable cutting head to be raised away from theground.

In regard to the cutting apparatus as they are discussed above, it ispreferred that the rotatable cutting head(s) is/are rotatable about ahead axis orientated to extend substantially transverse to the arm pivotaxis. Other arrangements or configurations of the rotatable cutting headare also contemplated, including but not limited to a configuration asdisclosed, for example, in U.S. Pat. No. 8,690,262 B2.

It is noted that the engaging members do not necessarily have to havedirect contact with the floor, the roof and/or the side wall(s), as longas the function of stabilizing the cutting apparatus is fulfilled; asthere might as well be indirect contact, e.g. in that further elements(not being part of the cutting apparatus as such) may be present betweenthe engaging members and the floor, roof or side wall(s).

The further objectives are achieved by providing a cutting apparatushaving a plurality of rotatably mounted cutting heads that may bepivoted in an upward and downward direction and a lateral side-to-sidedirection via a plurality of independently pivoting booms mounted at amain frame. In particular, each boom comprises a support pivotallymounted to the main frame and carrying an arm via a respectiveadditional pivot mounting such that each cutting head is capable ofpivoting about two pivoting axes. The desired range of movement of eachhead is provided as the dual pivoting axes are aligned transverse(including perpendicular) to one another and are spaced apart in thelongitudinal direction of the apparatus between a forward and rearwardend.

Advantageously, the cutting heads comprise a plurality of disc-likeroller cutters distributed circumferentially around a perimeter of eachhead so as to create a groove or channel into the rock face as the headsare driven about their respective rotational axes. The heads may then beraised vertically so as to overcome the relatively low tensile strengthof the overhanging rock to provide breakage via force and energy that isappreciably lower than a more common compressive cutting action providedby cutting picks and the like.

According to a further aspect of the present invention there is providedcutting apparatus suitable for creating tunnels or subterranean roadwaysand the like comprising: a main frame having generally upward, downwardand side facing regions; a first and second support pivotally mountedrelative to the main frame via respective first and second support axesaligned generally upright relative to the upward and downward facingregions such that each first and second support is configured to pivotlaterally in a sideways direction relative to the side facing regions;at least one first and second support actuator to respectively actuateindependently movement of each of the first and second supports relativeto the main frame; a first and second arm each pivotally mounted to therespective first and second support via a respective arm pivot axisaligned in a direction extending transverse including perpendicular toeach support pivot axis to enable the first and second arms to pivotindependently of one another and to pivot relative to each of therespective first and second supports in an upward and downward directionrelative to the upward and downward facing regions; at least one firstand second arm actuator to actuate independently pivoting movement ofthe first and second arms relatives to each of the respective first andsecond support; a rotatable cutting head mounted at each of the firstand second arms, each head rotatable about a head axis orientated toextend substantially transverse to each respective arm pivot axis.

Reference within this specification to each head being rotatable about ahead axis orientated to extend substantially transverse to eachrespective arm pivot axis includes (or encompasses) a perpendicularalignment. Such a reference also encompasses the respective pivot axesintersecting or more preferably not intersecting with the rotationalaxes of the cutting heads. Optionally, the rotational axes of thecutting heads are positioned generally in front of and/or above therespective pivot axes of the pivot arms.

Optionally, each cutting head comprises a generally annular cutting edgeor layered cutting edges to provide an undercutting mode of operation.The configuration of each head to provide the undercutting action isadvantageous to break the rock with less force and in turn provide amore efficient cutting operation that draws less power.

Preferably, the apparatus comprises a plurality of roller cuttersindependently rotatably mounted at each rotatable cutting head.Preferably, the roller cutters are generally annular roller cutters eachhaving a generally annular cutting edge or layered cutting edges toprovide an undercutting mode of operation. More preferably, the rollercutters are mounted at a perimeter region of each cutting head such thatthe roller cutters circumferentially surround each cutting head. Such aconfiguration is advantageous to provide the undercutting action of theapparatus with the roller cutters first creating a channel or grooveextending generally horizontally in the rock face. The roller cuttersmay then be moved upwardly to break the rock by overcoming the tensileforces immediately above the channel or groove. A more efficient cuttingoperation is provided requiring less force and drawing less power.Preferably, the roller cutters are mounted at generally cylindricalbodies and comprise generally annular cutting edges distributed aroundthe perimeter of the cutting head. Each generally circular cutting edgeis accordingly positioned side-by-side around the circumference of thecutting head with each cutting edge representing an endmost part of eachpivoting arm. Preferably an alignment of the rotational axes of theroller cutters relative to the rotational axis of the respective cuttinghead is the same so that the respective cutting edges are all orientatedin the same position around the cutting head.

Preferably, each of the first and second arm actuator comprises aplanetary gear assembly mounted at the junction at which each arm pivotsrelative to each support. The subject invention may comprise aconventional planetary gear arrangement such as a Wolfram type planetarygear having a high gear ratio. The planetary gear assembly is mountedinternally with each arm such that the cutting apparatus is designed tobe as compact as possible. Preferably, the apparatus further comprisesat least one first drive motor to drive the pivoting movement of thefirst and/or second arm relative to the respective first and secondsupport and the main frame. Preferably, the apparatus comprises twodrive motors to drive each of the first and second arms about theirpivoting axis via the respective planetary gears. Preferably, therespective drive motors are mounted in-board of each arm and are coupledto each arm via the planetary gear assembly and/or an intermediate drivetransmission.

Preferably, the apparatus further comprises at least one second drivemotor to drive rotation of the cutting head at the first and/or thesecond arm. Preferably, each head comprises two drive motors mounted atthe side of each arm. Such an arrangement is advantageous to pivot eachdrive motor with each cutting head and to provide a direct drive withminimal intermediate gearing.

Optionally, the first and second support actuator comprises a hydrauliclinear actuator. Preferably, each support actuator comprises a linearhydraulic cylinder positioned at the lateral sides of the sled andcoupled to extend between the sled and an actuating flange extendinglaterally outward from each support. Such an arrangement is advantageousto minimise the overall width of the apparatus whilst providing anefficient mechanism for the sideways lateral slewing of each support andaccordingly each arm.

Optionally, the sled may be positioned to operate longitudinally betweenthe supports and each of the respective arms. That is, each arm may beconfigured to slide in the axially forward direction relative to eachsupport via one or a plurality of actuators. Optionally, each arm isconnected to each support via a respective sliding actuator such thateach arm is configured to slide independently relative to one another.Optionally, each arm may be configured to slide in a forward andrearward direction relative to each support via a coordinated parallelsliding mechanism.

Preferably, the apparatus further comprises a powered sled movablymounted at the main frame to be configured to slide in a forward cuttingdirection of the apparatus relative to the main frame. The apparatus mayfurther comprise a plurality of ‘runners’ or guide rails to minimise thefrictional sliding movement of the sled over the main frame. Preferably,the apparatus comprises at least one powered linear actuator to providethe forward and rearward movement of the sled relative to the mainframe. As will be appreciated, the sled may be configured to moveaxially/longitudinally at the machine via a plurality of differentactuating mechanisms including rack and pinion arrangements, belt drivearrangements, gear arrangements and the like. Preferably the supportsand the arms are mounted at the sled and are all configured to move inthe forward and rearward direction collectively.

Optionally, each of the first and second arms is configured to pivot inthe upward and downward direction by up to 180°. Optionally, each armmay be configured to pivot over a range of up to 155°. Optionally, thefirst and second supports are configured to pivot in the lateralsideways direction by up to 90°. Optionally, the supports may beconfigured to pivot up to 20° in the lateral sideways direction. Such aconfiguration provides control of the profile shape and avoids any cutsor ridge that would otherwise remain on the roof and floor of theas-formed tunnel.

Preferably, the apparatus comprises tracks or wheels mounted at the mainframe to allow the apparatus to move in a forward and rearwarddirection. The tracks or wheels enable the apparatus to be advancedforwardly and rearwardly within the tunnel both when manoeuvred into andfrom the cutting face between cutting operations and to be advancedforwardly during cutting operations as part of the cut-and-advancecutting cycle that also utilises the sliding sled.

Preferably, the apparatus further comprises floor and roof engagingmembers mounted at the main frame, at least the floor engaging membersbeing extendable and retractable to respectively raise and lower theapparatus in the upward and downward direction. The engaging members areconfigured to wedge the apparatus in position between the roof and floorof the tunnel to provide points of anchorage against which the machinemay be braced to allow the cutters to be forced against the rock face.

Preferably, the apparatus further comprises a first material dischargeconveyor to convey cut material rearwardly from the first and secondcutting head; and a gathering head to direct cut material onto theconveyor, the gathering head positioned rearwardly behind at least oneof the first and second cutting heads. The apparatus is accordinglyconfigured to transport rearwardly material from the cut face to provideunhindered forward cutting movement into the rock.

Preferably, the apparatus further comprises a control unit demountablyconnectable to the apparatus, the control unit comprising operationalcomponents to power at least the first and second support and armactuators, the control unit further comprising a second conveyor toreceive material from the first conveyor and to discharge the materialat a position rearward of the apparatus and the control unit.Preferably, the control unit is demountably coupled to the apparatus soas to be capable of being advanced and retracted in the forward andrearward directions with the cutting apparatus. Preferably, the controlunit is suspended above the tunnel floor by suitable couplings to theapparatus. The control unit may comprise ground engaging support membersprovided at a rearward and/or forward regions. Optionally, the controlunit may be attachable at its rearward end to a material collection anddischarge vehicle and to be connectable at its forward end to thecutting apparatus.

According to a further aspect of the present invention there is providedcutting apparatus suitable for creating tunnels or subterranean roadwaysand the like comprising: a main frame having generally upward, downwardand side facing regions; a powered sled movably mounted at the mainframe to be configured to slide in a forward cutting direction of theapparatus relative to the main frame; a first and second arm pivotallycoupled or mounted to the sled by respective pivot arm axes aligned in adirection extending transverse including perpendicular to a longitudinalaxis of the main frame to allow each arm to pivot independently of oneanother in an upward and downward direction relative to the upward anddownward facing region of the main frame; at least one first and secondarm actuator to actuate independent pivoting movement of the first andsecond arms relative to one another and the main frame; a rotatablecutting head mounted at each of the first and second arms so as to beconfigured to be moved in the upward and downward direction and advancedin the forward cutting direction, each head rotatable about a head axisorientated to extend substantially transverse to respective pivot armaxes.

Optionally, the first and second arm together with the respective pivotarm axes are respectively coupled or mounted to the sled via a first andsecond support, the first and second supports are slidably mountedrelative to the sled via a common or respective slidable means such thateach first and second support is configured to slide laterally in asideways direction relative to the side facing regions. The first andsecond supports are mounted at the sled and configured to slidelaterally cross the sled substantially perpendicular to the forward andbackward sliding movement of the sled relative to the main frame.

Optionally, each rotatable cutting head comprises a generally annularroller cutter each having a generally annular cutting edge or layeredcutting edges to provide an undercutting mode of operation.

Preferably, the apparatus further comprises a plurality of rollercutters independently rotatably mounted at each rotatable cutting head.Optionally, the plurality of roller cutters is generally annular rollercutters each having a generally annular cutting edge or layered cuttingedges to provide an undercutting mode of operation.

According to a further aspect of the present invention there is providedcutting apparatus configured to create a cutting profile via anundercutting operation to create tunnels and subterranean roadways, theapparatus comprising: a main frame; a first and second arm pivotallymounted to the main frame by respective pivot arm axes aligned in adirection extending transverse including perpendicular to a longitudinalaxis of the main frame to allow each arm to pivot independently of oneanother in an upward and downward direction relative to an upward anddownward facing region of the main frame; at least one first and secondarm actuator to actuate independent pivoting movement of the first andsecond arms relative to one another and the main frame; a rotatablecutting head mounted at each of the first and second arms, each cuttinghead comprising generally annular roller cutters each having a generallyannular cutting edge to provide an undercutting mode of operation.

Preferably, the apparatus comprises a first and second support pivotallymounted relative to the main frame via respective first and secondsupport axes aligned generally upright relative to the upward anddownward facing regions such that each first and second support isconfigured to pivot laterally in a sideways direction relative to theside facing regions.

Preferably, the apparatus further comprises a powered sled movablymounted at the main frame, the first and second arms mounted at the sledso as to be capable of longitudinal reciprocating movement to slide in aforward cutting direction of the apparatus to engage the roller cuttersinto the rock face.

BRIEF DESCRIPTION OF DRAWINGS

A specific implementation of the present invention will now bedescribed, by way of example only, and with reference to theaccompanying drawings in which:

FIG. 1 is a front perspective view of a mobile cutting apparatussuitable for creating tunnels or subterranean roadways having a forwardmounted cutting unit and a rearward control unit according to a specificimplementation of the present invention;

FIG. 2 is a rear perspective view of the cutting apparatus of FIG. 1;

FIG. 3 is a side elevation view of the apparatus of FIG. 2;

FIG. 4 is a magnified front perspective view of the cutting unit of theapparatus of FIG. 3;

FIG. 5 is a plan view of the cutting apparatus of FIG. 4;

FIG. 6 is a side elevation view of the cutting apparatus of FIG. 5;

FIG. 7 is a front end view of the cutting apparatus of FIG. 6;

FIGS. 8 to 10 are simplified side elevation views of a cutting apparatusaccording to the invention in different modes; and

FIG. 11 is a schematic flow diagram illustrating a method according tothe invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION

Referring to FIG. 1, cutting apparatus 100 comprises a main frame 102mounting a plurality of cutting components configured to cut into a rockor mineral face to create tunnels or subterranean roadways. Apparatus100 is configured specifically for operation in an undercutting mode inwhich a plurality of rotatable roller cutters 127 may be forced into therock to create a groove or channel and then to be pivoted verticallyupward so as to overcome the reduced tensile force immediately above thegroove or channel and break the rock. Accordingly, the present cuttingapparatus is optimised for forward advancement into the rock or mineralutilising less force and energy typically required for conventionalcompression type cutters that utilise cutting bits or picks mounted atrotatable heads. However, the present apparatus may be configured withdifferent types of cutting head to those described herein including inparticular pick or bit type cutting heads in which each pick isangularly orientated at the cutting head to provide a predeterminedcutting attack angle.

Referring to FIGS. 1 to 3, main frame 102 comprises lateral sides 302 tobe orientated towards the wall of the tunnel; an upward facing region300 to be orientated towards a roof of the tunnel; a downward facingregion 301 orientated to be facing the floor of the tunnel; a forwardfacing end 303 intended to be positioned facing the cutting face and arearward facing end 304 intended to be positioned facing away from thecutting face.

An undercarriage 109 is mounted generally below main frame 102 and inturn mounts a pair of crawler tracks 103 driven by a hydraulic (orelectric) motor to provide forward and rearward movement of apparatus100 over the ground when in a non-cutting mode. A pair of rear groundengaging jacking legs 106 are mounted at frame sides 302 towardsrearward end 304 and are configured to extend and retract linearlyrelative to frame 102. Frame 102 further comprises a forward pair ofjacking legs 115 also mounted at each frame side 302 and towards forwardend 303 and being configured to extend and retract to engage the floortunnel. By actuation of legs 106, 115, main frame 102 and in particulartracks 103 may be raised and lowered in the upward and downwarddirection so as to suspend tracks 103 off the ground to positionapparatus 100 in a cutting mode. A pair of roof engaging grippers 105project upwardly from main frame 102 at frame rearward end 304 and areextendable and retractable linearly in the upward and downward directionvia control cylinders 116. Grippers 105 are therefore configured to beraised into contact with the tunnel roof and in extendable combinationwith jacking legs 106, 115 are configured to wedge apparatus 100 in astationary position between the tunnel floor and roof when in thecutting mode.

A sled 104 is slidably mounted on top of main frame 102 via a slidemechanism 203. Sled 104 is coupled to a linear hydraulic cylinder 201such that by reciprocating extension and retraction of cylinder 201,sled 104 is configured slide linearly between frame forward and rearwardends 303, 304.

A pair of hydraulically actuated bolting units 107 is mounted at mainframe 102 between sled 104 and roof gripping unit 105, 116 relative to alengthwise direction of the apparatus. Bolting units 107 are configuredto secure a mesh structure (not shown) to the roof of the tunnel asapparatus 100 is advanced in a forward cutting direction. Apparatus 100also comprises a mesh support structure (not shown) mounted generallyabove sled 104 so as to positionally support the mesh directly below theroof prior to bolting into position.

A pair of supports 120 are pivotally mounted at and project forwardlyfrom sled 104 immediately above frame forward end 303. Supports 120 aregenerally spaced apart in a lateral widthwise direction of the apparatus100 and are configured to independently pivot laterally outward from oneanother relative to sled 104 and main frame 102. Each support 120comprises a forward end 503 and a rearward end 504 referring to FIG. 5.A first mount flange 118 is provided at support rearward end 504 beinggenerally rearward facing. A corresponding second mount flange 119projects laterally outward from a side of sled 104 immediately behindthe first flange 118. A pair of linear hydraulic cylinders 117 ismounted to extend between flanges 118, 119 such that by linear extensionand retraction, each support 120 is configured to pivot in the generallyhorizontal plane and in the lateral sideways direction relative to framesides 302. Referring to FIG. 4, each support 120 is mounted at sled 104via a pivot rod 404 extending generally vertically (when apparatus 100is positioned on horizontal ground) through sled 104 and being suspendedgenerally above the main frame forward end 303. Each support 120 istherefore configured to pivot or slew about pivot axis 400. Referring toFIG. 5, each support 120 is further coupled to a respective innerhydraulic cylinder 500 mounted at an inner region of sled 104 tocooperate with side mounted cylinders 117 to laterally slew each support120 about pivot axis 400.

Referring to FIGS. 4 and 5, as the respective pivot axes 400 are spaceapart in the widthwise direction of apparatus 100, supports 120 arecapable of being slewed inwardly to a maximum inward position 501 and tobe slewed laterally outward to a maximum outward position 502. Accordingto the specific implementation, an angle between the inner and outerslewing positions 501, 502 is 20°.

Referring to FIGS. 1 to 3, an arm 121 is pivotally mounted generally atthe forward end 503 of each support 120. Each arm 121 comprises acutting head 128 rotatably mounted at a distal end. Each cutting head128 comprises a disk like (generally cylindrical) configuration. Theplurality of generally annular or disc shaped roller cutters 127 aremounted at the circumferential perimeter of each head 128 and comprise asharp annular cutting edge configured specifically for undercutting therock. Cutters 127 are rotatably mounted independently relative to oneanother and head 128 and are generally free to rotate about their ownaxis. Each roller cutter 127 projects axially beyond a forwardmostannular edge of head 128 such that when arms 121 are orientated to beextending generally downward, roller cutters 127 represent a lowermostpart of the entire head 128 and arm 121 assembly. Each arm 121 may beconsidered to comprise a length such that arm 121 is mounted at eachrespective support 120 at or towards a proximal arm end and to mounteach head 128 at a distal arm end. In particular, each arm 121 comprisesan internally mounted planetary gear indicated generally be reference122. Each gear 122 is preferably a Wolfrom type and is coupled to adrive motor 130 via a drive train indicated generally by reference 123.A pair of drive motors 125 is mounted at the lateral sides of each arm121 and is orientated to be approximately parallel with the rotationalaxis of each respective cutting head 128 as shown in FIG. 7. Each arm121 further comprise an internal drive and gear assembly 124 coupled toa gear box 126 mounted at one end of each of the drive motors 125. Eachcutting head 128 is driveably coupled to the drive motors 125 via therespective gear assembly 124 to provide rotation of cutting head 128about axis 402.

According to the specific implementation, and as shown in FIG. 7, eacharm 121 is coupled to a respective motor 130 mounted at a forward end ofsled 104. Each planetary gear 122 is centred on a pivot rod 405 having apivot axis 401 referring to FIG. 4. Each axis 401 is aligned to begenerally horizontal when apparatus 100 is positioned on horizontalground. Accordingly, each arm 121 is configured to pivot (relative toeach support 120, sled 104 and main frame 102) in the upward anddownward direction (vertical plane) by actuation of each motor 130. Assuch, each cutting head 128 and in particular the roller cutters 127 maybe raised and lowered along the arcuate path 602 referring to FIG. 6. Inparticular, each arm 121, head 128 and roller cutters 127 may be pivotedbetween a lowermost position 601 and an uppermost raised position 600with an angle between positions 600, 601 being approximately 150°. Whenin the lowermost position 601, each roller cutter 127 and in particularhead 128 is suspended in a declined orientation such that a forwardmostroller cutter 127 is positioned lower than a rearwardmost roller cutter127. According to the specific implementation, this angle of declinationis 10°. This is advantageous to engage the cutters 127 into the rockface at the desired attack angle to create the initial groove or channelduring a first stage of the undercutting operation. Additionally, theextensive range of movement of the cutting heads 128 over the rock faceis possible due, in part, to axis 401 being separated and positionedforward relative to axis 400 by a distance corresponding to a length ofeach support 120.

Referring to FIG. 4, each support pivot axis 400 is aligned generallyperpendicular to each arm pivot axis 401. Additionally, a rotationalaxis 402 of each cutting head 128 is orientated generally perpendicularto each arm pivot axis 401. A corresponding rotational axis 403 of eachroller cutter 127 is angularly disposed relative to cutting head axis402 so as to taper outwardly in the downward direction. In particular,each roller cutter axis 403 is orientated to be aligned closer to theorientation of each cutting head rotational axis 402 and support pivotaxis 400 relative to the generally perpendicular arm rotational axis401.

Accordingly, each support 120 is configured to slew laterally outward ina horizontal plane about each support axis 400 between the extreme innerand positions 501, 502. Additionally and referring to FIG. 6, eachrespective arm 121 is configured to pivot in the upward and downwarddirection about arm pivot axis 401 to raise and lower the roller cutters127 between the extreme positions 600, 601.

A gathering head 129 is mounted at main frame forward end 303immediately rearward behind each cutting head 128. Gathering head 129comprises a conventional shape and configuration having side loadingaprons and a generally inclined upward facing material contact face toreceive and guide cut material rearwardly from the cutting face (andcutting heads 128). Apparatus 100 further comprises a first conveyor 202extending lengthwise from gathering head 129 to project rearwardly fromframe rearward end 304. Accordingly, material cut from the face isgathered by head 129 and transported rearwardly along apparatus 100.

Referring to FIGS. 1 to 3, a detachable control unit 101 is mounted tothe frame rearward end 403 via a pivot coupling 200. Control unit 111comprises a personnel cabin 110 (to be occupied by an operator). Unit111 further comprises an electric and hydraulic power pack 114 tocontrol the various hydraulic and electrical components of apparatus 100associated with the pivoting movement of supports 120 and arms 121 inaddition to the sliding movement of sled 104 and the rotational drive ofcutting heads 128.

Control unit 101 further comprises a second conveyor 112 extendinggenerally lengthwise along the unit 101 and coupled at its forwardmostend to the rearwardmost end of first conveyor 202. Unit 101 furthercomprises a discharge conveyor 113 projecting rearwardly from therearward end of second conveyor 112 at an upward declined angle.Accordingly, cut material is capable of being transported rearwardlyfrom cutting heads 128 along conveyors 202, 112 and 113 to be receivedby a truck or other transportation vehicle.

In use, apparatus 100 is wedged between the tunnel floor and roof viajacking legs 106, 115 and roof grippers 105. Sled 104 may then bedisplaced in a forward direction relative to main frame 102 to engageroller cutters 127 onto the rock face. Cutting heads 128 are rotated viamotors 125 that create the initial groove or channel in the rock face ata lowermost position. A first arm 121 is then pivoted about axis 401 viamotor 130 to raise roller cutters 127 along path 602 to achieve thesecond stage undercutting operation. The first support 120 may then beslewed in the lateral sideways direction via pivoting about axis 400 andcombined with the raising and lowering rotation of roller cutters 127creates a depression or pocket within the rock immediately forward ofthe first arm 121 and support 120. The second arm 121 and associatedhead 128 and cutters 127 are then actuated according to the operation ofthe first arm 121 involving pivoting in both the vertical and horizontalplanes. This sequential dual pivoting movement of the second arm 121 isindependent of the initial dual pivoting movement of the first arm 121.A phasing and sequencing of the pivoting of arms 121 about axes 401 andsupports 120 about axes 400 is controlled via control unit 111.

When the maximum forward travel of sled 104 is achieved, jacking legs106, 115 are retracted to engage tracks 103 onto the ground. Tracks 103are orientated to be generally declined (at an angle of approximately10° relative to the floor) such that when ground contact is made, theroller cutters 127 are raised vertically so as to clear the tunnelfloor. The apparatus 100 may then be advanced forward via tracks 103.Jacking legs 106, 115 may then be actuated again to raise tracks 103 offthe grounds and grippers 105 moved into contact with the tunnel roof torepeat the cutting cycle. A forwardmost roof gripper 108 is mountedabove sled 104 to stabilise the apparatus 100 when sled 104 is advancedin the forward direction via linear actuating cylinder 201.

Referring to FIG. 8, which shows a simplified side elevation view of thecutting apparatus according to the invention, the cutting apparatusrests on the pair of crawler tracks 103 and is thus in a non-cuttingmode or a travel enabled mode, in which the cutting apparatus can moveforward or rearward on the pair of crawler tracks 103.

As discussed above, the crawler tracks 103 are mounted to a main frame102, on which further the sled 104 is mounted. The main frame 102 isfurther provided with the front pair of jacking legs 115 and the rearpair of jacking legs 106, which are retracted in the mode shown in FIG.8. Further, to the main frame 102 are mounted two rear roof engaginggrippers 105. The forward most roof gripper 108 is mounted to the sled104, which is further provided with the arm 121, to which the cuttinghead 128 is connected as discussed above. The roof grippers 105, 108 arealso retracted in the non-cutting mode, even though this is notnecessarily the case.

The pair of crawler tracks 103 rest on the ground 82. As the pair ofcrawler tracks and specifically a plane defined by the lower surfacethereof (which coincides with the ground 82 in FIG. 8) are inclined withrespect to longitudinal direction of the cutting apparatus (see alsoFIGS. 9 and 10), the cutting head 128 which is held by the arm 121 inbasically downwards direction is spaced apart (or raised from) theground 82 by a clearance 80. The clearance 80 allows that the cuttingapparatus can move without the cutting head 128 hitting the ground andwithout the need that the arm 121 would need to be pivoted in order todistance the cutting head 128 from the ground 82.

Referring to FIG. 9, in comparison to the case illustrated in FIG. 8,the front and rear jacking legs 106, 115 are extended and the cuttingapparatus rests on the jacking legs 106, 115. The cutting apparatus isarranged horizontally and the movement direction of the sled 104 isparallel to the ground 82. The inclination of the plane defined by thepair of crawler tracks 103 and the cutting apparatus can be seen byangle 81.

Referring to FIG. 10, the roof grippers 105, 108 are extended and are incontact with the roof 83, while in the case shown in FIG. 9, the roofgrippers are retracted.

With the extended roof grippers 105, 108, the cutting apparatus iswedged between the roof 83 and floor 82 as discussed above. As the pairof crawler tracks 103 is lifted from the ground 82, forces occurring incontext with the cutting operation are not exerted on the tracks 103.

The illustrations provided by FIGS. 8 to 10 are simplified, for example,in comparison to otherwise similar FIGS. 3 and 6. The simplificationsare provided for sake of explanation, while nevertheless the furtherfeatures discussed above with respect to FIGS. 1 to 7 may also beprovided for the cutting apparatus shown in FIGS. 8 to 10.

During cutting operation the cutting apparatus is stabilized (gripped)inside the tunnel as shown in FIG. 10. For relocation of the cuttingapparatus, as well as for moving the machine forward during a regripprocess the machine moves on crawlers (see FIG. 8).

To avoid that reaction forces from the cutting process are carried bythe crawler tracks 103, the apparatus is lifted off the floor by meansof the jacking legs 106, 115 as shown in FIGS. 9 and 10; two frontjacking legs 115, one on each side of the main frame 102, and two rearjacking legs 106, one on each side of the main frame 102.

In addition of lifting the machine, the jacking legs 106, 115 (supports)also may serve to adjust the cutting apparatus' cutting direction interms of pitch (inclination) and roll.

The crawler tracks 103 are arranged on the main frame at an angle 81towards the longitudinal cutting direction, such that the apparatustilts (in result) backwards when lowered on the floor, thus providingclearance 80 for the cutter heads from the floor or ground 82 duringmoving the cutting apparatus on the crawler tracks 103.

To ensure maximum machine stability during cutting, the cuttingapparatus is equipped with a gripping system comprising two top reargrippers 105, mounted on the main frame 104, and one top front gripper108 mounted on the sled 104.

After lifting the main frame 102 (and thus the cutting apparatus) offthe floor and adjusting the cutting direction by means of the supportsthe two top rear grippers 105 are extended and engaged with the roof 83providing active force to the roof by means of hydraulic cylinders.

During a sump in process, when sled 104 carrying the arms 121 andcutting heads 128 moves forward on guides in the main frame 104 the topfront gripper 108 remains retracted. After reaching the final sumpposition the top front gripper 108 is extended and engaged with the roof82 providing also active force to the roof 82.

FIG. 11 is a schematic flow diagram illustrating a method according tothe invention. The discussion of the method illustrated in FIG. 11starts at a situation where an undercutting step is completed and thearm(s) carrying the cutting head(s) return (step 701) to a lowermostposition (see 601 in FIG. 6). The front roof gripper is retracted (step702), followed by a return (step 703) of the sled to the rearmostposition. Once the sled is returned, the rear top grippers are retracted(step 704). As the next step the rear jacking legs are retracted (step705), followed by retracting (step 706) the front jacking legs.

The retraction of the rear jacking legs in step 705 results in abackwards tilt (counter clock wise in the illustration of FIGS. 8 to 10,for example) of the cutting machine, which is partially reversed (orreduced) by retracting the front jacking legs in step 706. During theretraction of the rear jacking legs in step 705, the cutting apparatustilts or pivots around an axis which basically corresponds to thecontact position of the front jacking legs with the ground. During afirst portion of the retraction of the front portion, there is aforwards tilt (clockwise in the illustration of FIGS. 8 to 10, forexample), corresponding to a pivoting around an axis which basicallycorresponds to the contact position of the rear jacking legs with theground. Once, however, the rear portion of the crawler tracks come intocontact with the ground, the pivot axis shifts to such contact point.

Eventually, the cutting machine rests on the crawler tracks and thus canbe moved (step 707) by operation of the crawler tracks.

Once the desired position on the ground is reached by movement on thecrawler tracks, the front jacking legs are extended (step 708), followedby extension of the rear jacking legs (step 709). In this situation, thecutting apparatus again rests on the jacking legs.

To secure the cutting apparatus in such position, the top rear grippersare extended (step 710), allowing for a sump in (step 711) including aforward movement of the sled to bring the cutting head forward. Once thesump in is completed, also the top front gripper is extended (step 712),completing the wedging of the cutting apparatus between floor and roofby means of the grippers and the jacking legs.

This is followed by an undercutting (step 713), during which the cuttinghead is brought upwards in a pivoting movement (position 601 to position600 along arc 602 in FIG. 6).

Depending on whether or not the sled can move further forward inrelation to the main frame (determination in step 714), the processeither continues to step 715 or returns to step 701.

In case a further forward movement is possible, in step 715, there is areturn of the cutting head to the initial position (see 601 in FIG. 6),followed by a retraction (step 716) of the top front gripper, thusallowing for a movement of the sled in relation to the main frame. Afterstep 716, the process returns to step 711.

In case no further forward movement of the sled in relation to the mainframe is possible (i.e. there have already been multiple loops of steps711 to step 716), the process returns to step 701, eventually allowingfor a movement of the complete cutting apparatus.

It is not necessarily the case that the steps 701 to 704, for example,are carried out in sequence in the sense that a later step starts onlyafter an earlier step is finished. It is also possible to provide atleast some of these steps at least partially in parallel.

Further, if desired, the retracting of the front and rear jacking legscan be carried out (at least partially) in parallel such that theattitude of the cutting apparatus is first brought (gradually) to beingparallel to the ground, such that the cutting apparatus is put on thecrawler tracks so that basically the crawler tracks touch the groundfrom front to end at the same time.

Yet further, provided that the cutting head(s) and the overallarrangement of the cutting apparatus allow for such operation, theretracting of the jacking legs may be provided in such manner that for acertain portion thereof the cutting apparatus partially rests on thecutting head (e.g. by first retracting the front jacking legs and thenretracting the rear jacking legs to put the cutting apparatus on thecrawler tracks).

EXEMPLARY EMBODIMENTS Embodiment 1

Cutting apparatus (100) suitable for creating tunnels or subterraneanroadways and the like comprising:

a main frame (102) having generally upward (300), downward (301) andside (302) facing regions;

a first and second support (120) pivotally mounted relative to the mainframe (102) via respective first and second support axes (400) alignedgenerally upright relative to the upward (300) and downward (301) facingregions such that each first and second support (120) is configured topivot laterally in a sideways direction relative to the side (302)facing regions;

at least one first and second support actuator (117) to respectivelyactuate independently movement of each of the first and second supports(120) relative to the main frame (102);

a first and second arm (121) each pivotally mounted to the respectivefirst and second (120) support via a respective arm pivot axis (401)aligned in a direction extending transverse including perpendicular toeach support pivot axis (400) to enable the first and second arms (121)to pivot independently of one another and to pivot relative to each ofthe respective first and second supports (120) in an upward and downwarddirection relative to the upward (300) and downward (301) facingregions;

at least one first and second arm actuator (122, 130) to actuateindependently pivoting movement of the first and second arms (121)relatives to each of the respective first and second support (120);

a rotatable cutting head (128) mounted at each of the first and secondarms (121), each head (128) rotatable about a head axis (402) orientatedto extend substantially transverse to each respective arm pivot axis(401).

Embodiment 2

The apparatus of embodiment 1 wherein each cutting head comprises agenerally annular cutting edge or layered cutting edges to provide anundercutting mode of operation.

Embodiment 3

The apparatus of embodiment 1 or 2 further comprising a plurality ofroller cutters (127) independently rotatably mounted at each rotatablecutting head (128).

Embodiment 4

The apparatus of embodiment claim 3 wherein the plurality of rollercutters (127) are generally annular roller cutters each having agenerally annular cutting edge or layered cutting edges to provide anundercutting mode of operation.

Embodiment 5

The apparatus of any one of the preceding embodiments wherein each ofthe first and second arm actuator (122, 130) comprises a planetary gearassembly mounted at the junction at which each arm (121) pivots relativeto each support (120).

Embodiment 6

The apparatus of any one of the preceding embodiments wherein at leastone of the first and second arm actuator (122, 130) comprises at leastone first drive motor to drive the pivoting movement of the first and/orsecond arm (121) relative to the respective first and second support(120).

Embodiment 7

The apparatus of any one of the preceding embodiments further comprisingat least one second drive motor (125) to drive rotation of the cuttinghead (128) at the first and/or the second arm (121).

Embodiment 8

The apparatus of any one of the preceding embodiments wherein the firstand second support actuator (117) comprises a hydraulic linear actuator.

Embodiment 9

The apparatus of any one of the preceding embodiments further comprisinga powered sled (104) movably mounted at the main frame (102) to beconfigured to slide in a forward cutting direction of the apparatus(100) relative to the main frame (102).

Embodiment 10

The apparatus of embodiment 9 wherein each of the first and secondcutting head (128) is mounted at the sled (104) via the respective firstand second arms (121) and supports (120) so as to be configured toadvance in the forward cutting direction.

Embodiment 11

The apparatus of any one of the preceding embodiments wherein:

each of the first and second arms (121) is configured to pivot in theupward and downward direction by up to 180°; and

each of the first and second supports (120) is configured to pivot inthe lateral sideways direction by up to 90°.

Embodiment 12

The apparatus of any one of the preceding embodiments further comprisingtracks (103) or wheels mounted at the main frame (102) to allow theapparatus (100) to move in a forward and rearward direction.

Embodiment 13

The apparatus of any one of the preceding embodiments further comprisingfloor and roof engaging members (106, 115, 105, 108) mounted at the mainframe (102), at least the floor engaging members (106, 115) beingextendable and retractable to respectively raise and lower the apparatus(100) in the upward and downward direction.

Embodiment 14

The apparatus of any one of the preceding embodiments furthercomprising:

a first material discharge conveyor (202) to convey cut materialrearwardly from the first and second cutting head (128); and

a gathering head (129) to direct cut material onto the conveyor (202),the gathering head (129) positioned rearwardly behind at least one ofthe first and second cutting heads (128).

Embodiment 15

The apparatus of embodiment 14 further comprising a control unit (101)demountably connectable to the apparatus (100), the control unit (101)comprising operational components (114) to power at least the first andsecond support (120) and arm actuators (122, 130), the control unit(101) further comprising a second conveyor (112) to receive materialfrom the first conveyor (202) and to discharge the material at aposition rearward of the apparatus (100) and the control unit (101).

Embodiment 16

Cutting apparatus (100) suitable for creating tunnels or subterraneanroadways and the like comprising:

a main frame (102) having generally upward (300), downward (301) andside (302) facing regions;

a powered sled (104) movably mounted at the main frame (102) to beconfigured to slide in a forward cutting direction of the apparatus(100) relative to the main frame (102);

a first and second arm (121) pivotally mounted to the sled (104) byrespective pivot arm axes (401) aligned in a direction extendingtransverse including perpendicular to a longitudinal axis of the mainframe (102) to allow each arm (121) to pivot independently of oneanother in an upward and downward direction relative to the upward anddownward facing region of the main frame (102);

at least one first and second arm actuator (122, 130) to actuateindependent pivoting movement of the first and second arms (121)relative to one another and the main frame (102);

a rotatable cutting head (128) mounted at each of the first and secondarms (121) so as to be configured to be moved in the upward and downwarddirection and advanced in the forward cutting direction, each head (128)rotatable about a head axis (402) orientated to extend substantiallytransverse to respective pivot arm axes (401).

Embodiment 17

The apparatus of embodiment 16 wherein each first and second arm (121)together with the respective pivot arm axes is respectively mounted tothe sled (104) via a first and second support (120) that is slidablymounted relative to the sled (104) via a common or respective slidablemeans such that each first and second support (120) is configured toslide laterally in a sideways direction relative to the side facingregions (302).

Embodiment 18

The apparatus of embodiment 16 or 17 wherein each rotatable cutting head(128) comprises a generally annular roller cutter (127) each having agenerally annular cutting edge or layered cutting edges to provide anundercutting mode of operation.

Embodiment 19

The apparatus of any one of embodiments 16 to 18 further comprising aplurality of roller cutters (127) independently rotatably mounted ateach rotatable cutting head (128).

Embodiment 20

The apparatus of embodiment 19 wherein the plurality of roller cutters(127) are generally annular roller cutters each having a generallyannular cutting edge or layered cutting edges to provide an undercuttingmode of operation.

Embodiment 21

The apparatus of any one of embodiments 17 to 20 wherein each of thefirst and second arm actuator (122, 130) comprises a planetary gearassembly mounted at the junction at which each arm (121) pivots relativeto each support.

The features of the embodiments presented hereinabove are understood tobe, alone or in combination with each other, preferred embodiments ofthe invention in themselves as well as in combination with what isclaimed hereinafter.

The invention claimed is:
 1. A cutting apparatus suitable for creatingtunnels or subterranean roadways and the like comprising: a main framehaving generally upward, downward and side facing regions; at least onearm pivotally mounted via an arm pivot axis aligned in a directionextending transverse including perpendicular to a generally uprightdirection relative to the upward and downward facing regions to pivotthe arm relative to the main frame in an upward and downward directionrelative to the upward and downward facing regions; at least one armactuator arranged to actuate pivoting movement of the arm relative tothe main frame; a rotatable cutting head mounted at the arm rotatableabout a head axis orientated to extend substantially transverse to thearm pivot axis; a pair of crawler tracks or a set of wheels arranged toprovide forward and rearward movement of the cutting apparatus overground; and a set of floor engaging members mounted at the main frame,wherein the floor engaging members are extendable to provide a cuttingmode of the cutting apparatus, in which the cutting apparatus rests onthe floor engaging members, and are retractable to provide a non-cuttingmode of the cutting apparatus, in which the cutting apparatus rests onthe pair of crawler tracks or set of wheels, the pair of crawler tracksor the set of wheels defining a plane inclined relative to the mainframe such that upon changing from the cutting mode to the non-cuttingmode the cutting head is raised away from the ground.
 2. The cuttingapparatus according to claim 1, wherein the inclination of the planedefined by the pair of crawler tracks or the set of wheels relative tothe main frame is in the range from 1° to 10°.
 3. The cutting apparatusaccording to claim 1, wherein the inclination of the plane defined bythe pair of crawler tracks or the set of wheels relative to the mainframe is set such that the cutting head is raised in an amount in therange from 3 cm to 30 cm.
 4. A cutting apparatus suitable for creatingtunnels or subterranean roadways and the like comprising: a main framehaving generally upward, downward and side facing regions; a poweredsled movably mounted at the main frame and configured to slide in aforward cutting direction of the cutting apparatus relative to the mainframe; at least one arm pivotally mounted to the sled via an arm pivotaxis aligned in a direction extending transverse including perpendicularto a generally upright direction relative to the upward and downwardfacing regions such that the arm is arranged to pivot relative to themain frame in an upward and downward direction relative to the upwardand downward facing regions; at least one arm actuator arranged toactuate pivoting movement of the arm relative to the main frame; arotatable cutting head mounted at the arm; and a plurality of engagingmembers mounted at the main frame, the engaging members including floorengaging members, roof or side wall engaging members, at least the floorengaging members being extendable and retractable to respectively raiseand lower the apparatus in the upward and downward direction, wherein atleast one of the roof or side wall engaging members being mounted to thepowered sled and configured to extend to wedge the cutting apparatus incooperation with the other engaging members in a cutting mode of thecutting apparatus between the roof or side wall and the floor.
 5. Thecutting apparatus according to claim 1, further comprising: a poweredsled movably mounted at the main frame and configured to slide in aforward cutting direction of the cutting apparatus relative to the mainframe, wherein the at least one arm is mounted to the sled; and a set ofroof or side wall engaging members mounted at the main frame, wherein atleast one roof or side wall engaging member is mounted to the poweredsled and is configured for being extended for wedging the cuttingapparatus in cooperation with the other engaging members in a cuttingmode of the cutting apparatus between roof or side wall and floor. 6.The cutting apparatus according to claim 1, wherein the floor engagingmembers are configured to arrange the cutting apparatus, during thecutting mode, such that the upward facing region is horizontal and/orparallel to the ground.
 7. The cutting apparatus according to claim 4,wherein the floor engaging members are configured to arrange the cuttingapparatus, during the cutting mode, such that a movement direction ofthe powered sled is parallel to the ground.
 8. The cutting apparatusaccording to claim 4, wherein the plurality of engaging members includetwo front floor engaging members, two rear engaging members, two roofengaging members mounted at the main frame, and the at least one roofengaging member mounted to the sled, wherein the two roof engagingmembers mounted to the main frame are at a position backwards inrelation to the sled.
 9. The cutting apparatus according claim 1,wherein the plurality of engaging members are each extendable andretractable linearly by a respective control cylinder.
 10. A method ofoperating a cutting apparatus for creating tunnels or subterraneanroadways and the like, the method comprising: providing a cuttingapparatus, the cutting apparatus including a main frame having generallyupward, downward and side facing regions, at least one arm pivotallymounted via an arm pivot axis aligned in a direction extendingtransverse including perpendicular to a generally upright directionrelative to the upward and downward facing regions to pivot the armrelative to the main frame in an upward and downward direction relativeto the upward and downward facing regions, at least one arm actuatorarranged to actuate pivoting movement of the arm relative to the mainframe, a rotatable cutting head mounted at the arm, a pair of crawlertracks or a set of wheels allowing a forward and rearward movement ofthe cutting apparatus over ground, and a set of floor engaging membersmounted at the main frame; a cutting step; a non-cutting step includinga forward or rearward movement of the cutting apparatus over ground; afirst transition step from the non-cutting step to the cutting stepincluding an extending of the floor engaging members such that thecutting apparatus rests on the floor engaging members; and a secondtransition step from the cutting step to the non-cutting step includinga retracting of the floor engaging members such that the cuttingapparatus rests on the pair of crawler tracks or set of wheels, whereinthe pair of crawler tracks or the set of wheels define a plane inclinedrelative to the main frame such that the second transition step includesa backward-tilting of the cutting apparatus, causing the rotatablecutting head to be raised away from the ground.
 11. The method accordingto claim 10, further comprising an adjustment step of adjusting adirection and/or position of the cutting apparatus by the floor engagingmembers and/or the pair of crawler tracks or set of wheels.
 12. A methodof operating a cutting apparatus for creating tunnels or subterraneanroadways and the like, comprising the steps of: providing a main framehaving generally upward, downward and side facing regions, a poweredsled movably mounted at the main frame and configured to slide in aforward cutting direction of the cutting apparatus relative to the mainframe, at least one arm pivotally mounted to the sled via an arm pivotaxis aligned in a direction extending transverse including perpendicularto a generally upright direction relative to the upward and downwardfacing regions to pivot the arm relative to the main frame in an upwardand downward direction relative to the upward and downward facingregions, at least one arm actuator arranged to actuate pivoting movementof the arm relative to the main frame, a rotatable cutting head mountedat the arm, and a plurality of engaging members mounted at the mainframe, the plurality of engaging members including floor engagingmembers and roof or side wall engaging members, at least the floorengaging members being extendable and retractable to respectively raiseand lower the apparatus in the upward and downward direction, wherein atleast one roof or side wall engaging member is mounted to the poweredsled; an anchoring step of extending at least the floor engaging membersso to wedge the cutting apparatus between the roof or side wall and thefloor; and an operation step including an extending of the at least oneroof or side wall engaging member mounted to the powered sled forcooperating with the other engaging members in wedging the cuttingapparatus between the roof or side wall and the floor.
 13. The methodaccording to claim 12, wherein the operation step further includes,after the extending of the at least one roof or side wall engagingmember, a cutting step including a pivoting of the arm relative to themain frame and a cutting by the cutting head, and wherein the operationstep further includes, after the cutting, a retracting of the at leastone roof or side wall engaging member and a moving of the sled.
 14. Themethod according to claim 13, wherein the operation step includesmultiple repetitions of the extending of the at least one roof or sidewall engaging member, the cutting step and the retracting of the atleast one roof or side wall engaging member and moving of the sled inthis order.
 15. The method according to claim 12, wherein the cuttingapparatus includes a pair of crawler tracks or a set of wheels allowinga forward and rearward movement of the cutting apparatus over ground,and the method further comprises a non-cutting step including a forwardor rearward movement of the cutting apparatus over ground, and a secondtransition step from the anchoring or operation step to the non-cuttingstep including a retracting of the floor engaging members such that thecutting apparatus rests on the pair of crawler tracks or set of wheels,the pair of crawler tracks or the set of wheels defining a planeinclined relative to the main frame such that the second transition stepincludes a backward-tilting of the cutting apparatus, causing therotatable cutting head to be raised away from the ground.